You will need to ask the Adobe admin of each of those organisations to add you with the common email address (Adobe ID) that you want to use, and also remove any other email address that you don't want to use with them any more.
Then, when you login with that one common email address (Adobe ID), you will be presented with a profile switcher where you can choose the organisation that you want to use. (Although with Analytics and really most other Experience Platform products, it doesn't matter which profile you choose, you'll still be able to access all of the organisations that your common email address has access to.)
Despite the above, I don't think there's a way to combine your rewards/achievements under that one common email address (Adobe ID). If you're a Solution Partner and are concerned about your certifications, you can reach out to SPP Help, and they can help you merge your certification accounts under the one that you want (which can also be a personal email address, instead of your organisation email address).